JP2008143226A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To positively ensure comfortableness and safety without causing a fault such as a cost increase and to efficiently utilize an inside air circulation mode. <P>SOLUTION: This air conditioner for a vehicle comprises an outside air intake port, an inside air intake port, an inside/outside air switching means for changing the inside/outside air ratio of air taken into a unit case, and a control means for controlling the inside/outside air switching means. The control means computes estimated CO<SB>2</SB>concentration in a cabin and outside air lead-in mode duration based on vehicle speed, an amount of blowoff air into the cabin, the number of occupants and inside air circulation mode duration when carrying out the inside air circulation mode, and carries out an outside air lead-in mode until the lapse of the outside air lead-in mode duration when the estimated CO<SB>2</SB>concentration exceeds a predetermined value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a vehicle air conditioner, and more particularly to a means for preventing an excessive increase in CO ₂ concentration in a passenger compartment.

In a vehicle air conditioner, there is a demand to increase the ratio of operating in the inside air circulation (recycle) mode as much as possible from the viewpoint of improving air conditioning efficiency and reducing fuel consumption. However, during the execution of the recycle mode, the CO ₂ concentration in the passenger compartment increases with time due to the breathing of passengers and the like. An increase in the CO ₂ concentration causes a headache, drowsiness, etc. to the occupant.

As an invention for preventing the adverse effects due to the increase in CO ₂ concentration as described above, a cleansing gas is generated by guiding the passenger compartment air and a blowout nozzle that is configured separately from the air conditioning unit and blows clean gas toward the passenger. A device equipped with a clean gas supply device for supplying clean gas to the blowout nozzle (see Patent Document 1), or air containing a large amount of oxygen from outside air or an oxygen enrichment device, and this air is used as a respiratory system for the occupant There is disclosed a fresh air passage that is supplied in a spot-like manner and a fresh air blower that generates an air flow toward the occupant's respiratory system in the fresh air passage (see Patent Document 2).
JP 2006-1319 A JP-A-6-171353

  However, in the configuration disclosed in Patent Document 1, a blow nozzle and a clean gas supply device (see Patent Document 1), and in the configuration disclosed in Patent Document 2, a fresh air passage and an oxygen enrichment device ( Patent Document 2) is required as equipment separate from the air conditioning unit. Such equipment causes problems such as an increase in cost, an increase in vehicle weight, and a reduction in living space.

  In view of the above, an object of the present invention is to ensure comfort and safety without causing problems such as an increase in cost and to make it possible to efficiently use the inside air circulation mode.

In order to solve the above-described problems, the present invention provides a unit case by changing the opening of an outside air inlet communicating with the outside of the vehicle, an inside air inlet communicating with the vehicle interior, the outside air inlet, and the inside air inlet. In a vehicle air conditioner comprising an inside / outside air switching means for changing an inside / outside air ratio of the taken-in air and a control means for controlling the inside / outside air switching means, the control means opens the inside air inlet and opens the outside air. When executing the inside air circulation mode in which the mouth is fully closed, based on the predetermined parameters, the estimated CO ₂ concentration in the passenger compartment and the outside air introduction mode duration required to ensure the comfort or safety of the occupant When the estimated CO ₂ concentration exceeds a predetermined value, an outside air introduction mode is executed in which the outside air intake port is opened at a predetermined opening until the outside air introduction mode duration time elapses. (Claim 1).

According to the above configuration, at the time of execution of the inside air circulation mode, the estimated CO ₂ concentration based on predetermined parameters (listed below) is calculated, if the estimated CO ₂ concentration exceeds a predetermined value, the outside air introduction mode This is executed for the duration of the outside air introduction mode calculated based on the parameters. As a result, outside air is introduced before the CO ₂ concentration in the passenger compartment increases until it adversely affects the occupant, so comfort and safety for the occupant can be reliably ensured. Then, after the outside air introduction mode duration has elapsed, the inside air circulation mode is executed again, so that the inside air circulation mode can be executed to the maximum extent within the range in which passenger comfort and safety are ensured. Efficiency can be improved. Thus, according to this configuration, it is possible to provide a vehicle air conditioner that achieves both comfort and safety for passengers and improved air conditioning efficiency. In addition, since this configuration can be realized by computer control, there is no need to install a special device, and an increase in cost can be minimized, such as an increase in vehicle weight and a reduction in living space. Does not occur.

Further, in the configuration according to claim 1, the parameters are vehicle speed, amount of air blown into the vehicle interior, number of passengers, duration of inside air circulation mode, and estimated CO ₂ concentration is vehicle speed, number of passengers, inside air circulation. Preferably, the outside air introduction mode duration is calculated based on the vehicle speed, the amount of air blown into the passenger compartment, the number of passengers, and the duration of the inside air circulation mode. .

The CO ₂ concentration in the passenger compartment in the inside air circulation mode is based on the vehicle speed, the number of passengers, and the duration of the inside air circulation mode, and the duration of the outside air introduction mode for ensuring comfort or safety is Can be estimated and calculated with high accuracy based on the amount of air blown out, the number of passengers, and the duration of the inside air circulation mode.

  Further, in the configuration according to claim 2, it is preferable that the control unit calculates an outside air introduction mode duration time executed at an outside air introduction rate of 100% (claim 3), and the configuration according to claim 3. The control means calculates an outside air introduction mode duration executed at an outside air introduction rate greater than 0% and less than 100% based on the outside air introduction mode duration executed at the outside air introduction rate of 100%. (Claim 4).

  First, by calculating the duration of the outside air introduction mode when executed at an outside air introduction rate of 100%, the durations at various outside air introduction rates can be derived based on this. For example, if the outside air introduction mode duration at the outside air introduction rate of 100% is T100, the outside air introduction mode duration T50 at the outside air introduction rate of 50% is T50 = 2 * T100.

As described above, according to the present invention, when the inside air circulation mode is executed, the estimated CO ₂ concentration and the outside air introduction mode duration time are calculated based on the vehicle speed, the air volume blown out from the vehicle interior, the number of passengers, and the inside air circulation mode duration time. When the estimated CO ₂ concentration exceeds a predetermined value, the outside air introduction mode is executed for the calculated outside air introduction mode duration. As a result, the inside air circulation mode can be executed as long as the CO ₂ concentration in the passenger compartment does not adversely affect the health of the passenger, ensuring safety for passengers and improving air conditioning efficiency. It is possible to provide a vehicle air conditioner that balances the above. In addition, according to the present invention, since it is not necessary to mount a special device on the vehicle, problems such as an increase in cost, an increase in vehicle weight, and a reduction in living space do not occur.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The air conditioning unit 1 shown in FIG. 1 includes an intake unit 2, a heat exchange unit 3, and an outlet selection unit 4. The intake portion 2 is a portion that takes air into the unit case 5. The heat exchange unit 3 is a part that adjusts the air taken in from the intake unit 2 to a set temperature or humidity. The blower outlet selection part 4 is a part for making the conditioned air adjusted by the heat exchange part 3 blow out selectively from the several blower outlet provided in the vehicle interior. Each of these portions 2, 3, and 4 may be provided as individual parts, or all or a part thereof may be integrated.

  The intake section 2 includes a blower 10, an outside air inlet 11, an inside air inlet 12, and an inside / outside air switching damper 13. A drive current is supplied from the in-vehicle battery, and air is taken into the unit case 5 from one or both of the outside air inlet 11 and the inside air inlet 12 by the blower 10 controlled by the electronic control unit (ECU) 15. The outside air inlet 11 communicates with the outside air, and the inside air inlet 12 communicates with the vehicle interior. The introduction ratio between the outside air and the inside air is adjusted by the inside / outside air switching damper 13 driven by the actuator 14, and the actuator 14 is controlled by the ECU 15. The ECU 15 performs various information processing necessary for the air conditioner, outputs control signals to components, and the like in cooperation with hardware such as a CPU, ROM, and RAM and predetermined program software.

  The heat exchange unit 3 includes an evaporator 20, a heater core 21, and an air mix door 22. The evaporator 20 is a heat exchanger into which the decompressed refrigerant flows in a well-known refrigeration cycle, and cools the air taken into the unit case 5 from the intake portion 2. The heater core 21 is a heat exchanger into which engine coolant is introduced, and heats the air that has passed through the evaporator 20. The amount of air passing through the heater core 21 is adjusted by an air mix door 22 driven by an actuator 23, and conditioned air having a set temperature (humidity) is generated by this adjustment. The actuator 23 is controlled by the ECU 15.

  The outlet selection unit 4 includes a vent communication port 25, a foot communication port 26, a defrost communication port 27, a vent opening / closing door 30, a foot opening / closing door 31, and a defrost opening / closing door 32. The vent communication port 25 is an opening that communicates with a vent outlet provided through the duct so as to be blown toward the passenger's upper body in the passenger compartment, and the bend door 30 is used to open or close or adjust the opening. The The foot communication port 26 is an opening that communicates via a duct with a foot outlet provided so as to blow air toward the feet of the occupant in the passenger compartment. The foot door 31 is used to open or close or adjust the opening. The The defrost communication port 27 is an opening that communicates via a duct with a defrost outlet that is provided so as to blow air toward the windshield in the vehicle interior. The The vent door 30, the foot door 31, and the defrost door 32 are driven by actuators 35, 36, and 37, respectively. These actuators 35, 36 and 37 are controlled by the ECU 15. The door 30, 31, 32 blows conditioned air from a desired outlet. Note that the above-described formation positions of the communication ports 25, 26, and 27, the structures of the doors 30, 31, and 32 are examples, and various other configurations can be employed.

A feature of the present invention resides in the control of the inside / outside air switching damper 13 by the ECU 15. In this control, on the basis of the following parameters, as well as estimating the CO ₂ concentration in the vehicle cabin in the inside air circulation (recycling) mode, the outside air introduced should be performed to prevent excessive enrichment of the passenger compartment of the CO ₂ Calculate duration of (fresh) mode. FIG. 2 shows an outline of information processing in the above control. As shown in the figure, in the ECU 15 according to the present invention, the vehicle speed Cs, the air volume Va blown into the vehicle interior, the number of passengers N, and the internal air circulation (REC.) Mode duration t are used as input parameters, and based on these parameters. Thus, the estimated CO ₂ concentration Cc in the passenger compartment and the duration T100 of the outside air introduction mode when the outside air introduction rate is 100% are output. Further, based on the duration time T100 of the 100% outside air introduction mode, the duration times T80, T50, T20 of the outside air introduction mode when the outside air introduction rate is set to 80%, 50%, 20%, etc. are derived as outputs. To do.

The vehicle speed Cs [km / h] can be detected by a normally used vehicle speed sensor. As the vehicle speed Cs increases, the amount of outside air taken in during the outside air introduction mode increases. The vehicle interior blown air volume Va [m ³ / hr] is the amount of air blown into the vehicle interior calculated from the feedback signal from the motor of the blower 10, the blowing capacity of the blower 10, and the like. The occupant number N is the number of persons existing in the passenger compartment and can be detected by a seating sensor or the like. As the number of passengers N increases, the amount of increase in CO ₂ concentration in the passenger compartment per unit time increases. The inside air circulation mode continuation time t [s] can be detected by a feedback signal from the actuator 14 of the inside / outside air switching damper 13 or the like.

As shown in FIG. 3, the ECU 15 includes a CO ₂ concentration estimation unit 41, an outside air introduction time calculation unit 42, and an actuator control unit 43. The CO ₂ concentration estimating means 41 calculates an estimated CO ₂ concentration Cc based on the vehicle speed Cs, the number of passengers N, and the inside air circulation mode duration t. A specific calculation formula is shown in the following formula 1.

In the above equation 1, β is a constant set according to the type of vehicle (indoor volume, cabin design, etc.), and in [km / h ⁻¹ ] as a unit, a smaller value is usually set as the indoor volume is larger. . λj is a constant that is set according to the type of car and the type of passenger (adult, child, etc.). The unit is [ppm / s], and a smaller value is usually set as the indoor volume is larger. Is set as a large value. Co is a constant set as an initial value of the CO ₂ concentration in units of [ppm].

In the following formula 2, vehicle speed Cs = 50 [km / h], number of passengers N = 3, inside air circulation mode duration t = 1800 [s], β = −0.004 [(km / h) ⁻¹ ], λ1 = 1.17 [ppm / s] (λ2 = 0, λ3 = 0 (adult only)) and Co = 1800 [ppm] are estimated CO ₂ concentrations Cc.

The above example is an estimated value of the CO ₂ concentration in the passenger compartment when a passenger of three adults is on a 1500 cc compact car class vehicle, travels at a vehicle speed of 50 km / h, and continues in the recycle mode for 30 minutes.

Further, the CO ₂ concentration estimating means 41 of the ECU 15 calculates a 100% outside air introduction mode execution time T100 based on the vehicle speed Cs, the vehicle interior blown air volume Va, the number of passengers N, and the inside air circulation mode duration time t. A specific calculation formula is shown in Equation 3 below.

In the above formula 3, α and νi are constants set by the type of vehicle (indoor volume, cabin design, etc.) and air-conditioning air outlet (vent, foot, etc.), and α is [s / ppm] , Νi is in units of [(m ³ / h) ⁻¹ ]. β, λj, and Co are the same as described above.

In the following equation 4, vehicle speed Cs = 50 [km / h], number of passengers N = 3, inside air circulation mode duration t = 1800 [s], α = 0.0395 [s / ppm], β = −0.004 [(km / h) ⁻¹ ], ν ¹ = 0.0044 [(m ³ / h) ⁻¹ ] (ν 2 = 0, ν 3 = 0 (vent only)), λ 1 = 1.17 [ppm / s] ( The 100% outside air introduction mode duration T100 is shown when λ2 = 0, λ3 = 0 (adult only)) and Co = 1800 [ppm].

In the above example, three adult passengers are placed on a 1500cc compact car class vehicle, traveling at a vehicle speed of 50 km / h, the air conditioner driven at an air flow rate of 120 m ³ / hr, and the recycle mode continued for 30 minutes , The execution time T100 of the 100% outside air introduction mode to be operated in order to prevent an excessive increase in the CO ₂ concentration.

Further, the CO ₂ concentration estimating means 41 is based on the 100% outside air introduction mode duration time T100, and the outside air introduction mode duration times T80, T50, T20 when the outside air introduction rate is 80%, 50%, 20%, etc. Can also be calculated. The outside air introduction mode duration Tx when the outside air introduction rate is x is calculated by the following equation (5).

  In other words, the outside air introduction mode duration T50 under the same conditions as in Equation 4 and the outside air introduction rate of 50% is twice T100 and is approximately 309.6 s.

  In FIG. 4, a control example of the actuator 14 of the inside / outside air switching damper 13 by the ECU 15 having the above-described configuration is shown in a flowchart. First, the inside air circulation (recycling) mode is executed, that is, the inside / outside air switching damper 13 is at a position where the outside air inlet 11 is blocked (two-dot chain line in FIG. 1), and the inside air circulation rate becomes 100%. Is determined (step 100), and if it is not the inside air circulation mode (N), the process is out of this flowchart.

If it is determined in step 100 that the inside air circulation mode is being executed (Y), the estimated CO ₂ concentration Cc and the 100% outside air introduction mode duration T100 are calculated by the above procedure (step 101). Next, it is determined whether the estimated CO ₂ concentration Cc exceeds a predetermined value Cr (step 102). As this predetermined value Cr, about 5000 ppm can be considered.

  If it is determined in step 102 that Cc> Cr is not satisfied (N), the process leaves the flowchart, and if it is determined that Cc> Cr is satisfied (Y), the outside air introduction rate x in the outside air introduction mode. Is set (step 103). The setting of the outside air introduction rate x can be determined by weather conditions, setting by an occupant, and the like. It is also preferable to always set it to 100% depending on the specifications. Next, an outside air introduction mode duration Tx corresponding to the set outside air introduction rate x is calculated by the above procedure based on T100 (step 104). For example, when the outside air introduction rate is 50%, T50 = 2 · T100. When the outside air introduction rate is 100%, T100 calculated in step 101 is used as it is, and Tx = T100. Next, the inside / outside air switching damper 13 is moved so as to achieve the outside air introduction rate x (step 105).

  Next, it is determined whether or not the duration T of the outside air introduction mode executed in step 105 exceeds the outside air introduction mode duration Tx calculated in step 104 (step 106). The inside / outside air switching damper 13 is moved to the inside air circulation (recycling) mode position (step 107). If not exceeded (N), the inside / outside air switching damper 13 is moved to the outside air introduction mode position until T> Tx. To maintain.

As described above, according to the present invention, when the inside air circulation mode is executed, the estimated CO ₂ concentration Cc and the outside air introduction mode are based on the vehicle speed Cs, the vehicle interior blowing air amount Va, the number of passengers N, and the inside air circulation mode duration time t. The duration time T100 (Tx) is calculated, and the outside air introduction mode is automatically executed before the CO ₂ concentration in the passenger compartment increases until it adversely affects the occupant's health. If the CO ₂ concentration decreases to the safe range by executing the outside air introduction mode, the inside air circulation mode is executed again. As a result, both safety for passengers and improvement of air conditioning efficiency can be achieved.

It is a figure which shows the structural example of the air conditioning unit with which this invention can be applied. It is a figure which shows the flow of the information processing by ECU. It is a figure which shows the means with which ECU, and the flow of information. It is a flowchart which shows the example of control of the actuator of the inside / outside air switching damper by ECU.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning unit 2 Intake part 10 Blower 11 Outside air inlet 12 Inside air inlet 13 Inside / outside air switching damper 14 Actuator 15 Electronic control unit (ECU)

Claims (4)

Outside / inside air that changes the ratio of inside / outside air in the unit case by changing the opening of the outside air inlet that communicates with the outside of the vehicle, the inside air inlet that communicates with the vehicle interior, the outside air inlet, and the inside air inlet Switching means;
Control means for controlling the inside / outside air switching means;
In a vehicle air conditioner comprising:
The control means, when executing the inside air circulation mode in which the inside air inlet is fully opened and the outside air inlet is fully closed, based on a predetermined parameter, the estimated CO ₂ concentration in the passenger compartment, passenger comfort or The outside air introduction mode duration required for ensuring safety is calculated, and when the estimated CO ₂ concentration exceeds a predetermined value, the outside air inlet is set to a predetermined amount until the outside air introduction mode duration elapses. A vehicle air conditioner that executes an outside air introduction mode that opens at an opening. The parameters are the vehicle speed, the amount of air blown into the passenger compartment, the number of passengers, the duration of the inside air circulation mode,
The estimated CO ₂ concentration is calculated based on the vehicle speed, the number of passengers, and the duration of the inside air circulation mode,
2. The vehicle air conditioner according to claim 1, wherein the outside air introduction mode duration is calculated based on a vehicle speed, an amount of air blown into the passenger compartment, the number of passengers, and a duration of the inside air circulation mode.   3. The vehicle air conditioner according to claim 2, wherein the control means calculates an outside air introduction mode duration time executed at an outside air introduction rate of 100%.   The control means calculates an outside air introduction mode duration that is executed at an outside air introduction rate that is greater than 0% and less than 100% based on the outside air introduction mode duration that is executed at the outside air introduction rate of 100%. The vehicle air conditioner according to claim 3.

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